job_inventory.go

//
//  tank
//
//  Import and Playlist Daemon for autoradio project
//
//
//  Copyright (C) 2017-2018 Christian Pointner <equinox@helsinki.at>
//
//  This file is part of tank.
//
//  tank is free software: you can redistribute it and/or modify
//  it under the terms of the GNU General Public License as published by
//  the Free Software Foundation, either version 3 of the License, or
//  any later version.
//
//  tank is distributed in the hope that it will be useful,
//  but WITHOUT ANY WARRANTY; without even the implied warranty of
//  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
//  GNU General Public License for more details.
//
//  You should have received a copy of the GNU General Public License
//  along with tank. If not, see <http://www.gnu.org/licenses/>.
//

package importer

import (
	"log"
	"sync"
)

type jobInventoryGroup struct {
	jobs map[uint64]*Job
	// add list of subscription channels
}

func newJobInventoryGroup() *jobInventoryGroup {
	g := &jobInventoryGroup{}
	g.jobs = make(map[uint64]*Job)
	return g
}

type jobInventory struct {
	infoLog *log.Logger
	errLog  *log.Logger
	dbgLog  *log.Logger
	groups  map[string]*jobInventoryGroup
	mu      sync.RWMutex
}

func (i *jobInventory) ListJobs(group string) (jobs Jobs) {
	i.mu.RLock()
	defer i.mu.RUnlock()

	ig, exists := i.groups[group]
	if !exists {
		return
	}

	for _, j := range ig.jobs {
		jobs = append(jobs, j)
	}
	return
}

func (i *jobInventory) InsertOrGetJob(group string, id uint64, jobIn *Job) (job *Job) {
	i.mu.Lock()
	defer i.mu.Unlock()

	ig, exists := i.groups[group]
	if !exists {
		ig = newJobInventoryGroup()
		ig.jobs[id] = jobIn
		i.groups[group] = ig
		i.dbgLog.Printf("importer: job-inventory added job(%s/%d)", group, id)
		return jobIn
	}

	if job, exists = ig.jobs[id]; !exists {
		ig.jobs[id] = jobIn
		i.dbgLog.Printf("importer: job-inventory added job(%s/%d)", group, id)
		return jobIn
	}

	return
}

func (i *jobInventory) GetJob(group string, id uint64) (job *Job, err error) {
	i.mu.RLock()
	defer i.mu.RUnlock()

	ig, exists := i.groups[group]
	if !exists {
		return nil, ErrNotFound
	}

	if job, exists = ig.jobs[id]; !exists {
		return nil, ErrNotFound
	}
	return
}

func (i *jobInventory) DeleteJob(group string, id uint64) (err error) {
	i.mu.Lock()
	defer i.mu.Unlock()

	ig, exists := i.groups[group]
	if !exists {
		return ErrNotFound
	}
	if _, exists = ig.jobs[id]; !exists {
		return ErrNotFound
	}

	delete(ig.jobs, id)
	i.dbgLog.Printf("importer: job-inventory removed job(%s/%d)", group, id)
	if len(ig.jobs) == 0 {
		// TODO: only do this if there are no subscriptions
		delete(i.groups, group)
		i.dbgLog.Printf("importer: job-inventory also removed now empty group %s", group)
	}
	return
}

// TODO: handle subscriptions to new and deleted jobs

func newJobInventory(infoLog, errLog, dbgLog *log.Logger) *jobInventory {
	i := &jobInventory{infoLog: infoLog, errLog: errLog, dbgLog: dbgLog}
	i.groups = make(map[string]*jobInventoryGroup)
	return i
}